A substance has half of 3 min. After 6 min, the count rate was observed to be 400. What was its count rate at zero time?

A few grains of table salt were put in a cup of cold water, kept at constant temperature and left undistributed. Eventually all the water tested salty. This ...

The effect of closing the key K in the circuit shown in the figure above would be to?

A machine gun with a mass of 5kg fires a 50g bullet at a speed of 100 ms ? 1 . The recoil speed of the machine gun is

Which of the following statements about radioactivity is true? (i) Alpha particle is positively charged (ii) Beta particle is negatively charged (iii) Gamma ...

The force required to make an object of mass m, travelling with velocity v, turn in a circle of radius r is

In the study of Physics, temperature and heat are often confused with each other. Which of the following statements correctly defines these two elements?

If in a simple pendulum experiment the length of the inextensible string is increased by a factor or four, its period is increased by a factor of?

In what range of temperature is the expansion of water anomalous?